1. Technical Field
The present disclosure relates to an LED lighting apparatus, and more particularly, to a control circuit and method of an LED lighting apparatus, which is capable of reducing total harmonic distortion (hereafter, referred to as “THD”).
2. Related Art
A lighting apparatus is designed to use a light source which exhibits high light emission efficiency using a small amount of energy, in order to reduce energy consumption. Representative examples of the light source used in the lighting apparatus may include an LED.
The LED is differentiated from other light sources in terms of various aspects such as energy consumption, lifetime, and light quality. Since the LED is driven by a current, the lighting apparatus using the LED as a light source needs many additional circuits for current driving.
In order to solve the above-described problem, an AC direct-type lighting apparatus has been developed. The AC direct-type lighting apparatus is configured to convert an AC voltage into a rectified voltage, and drive a current using the rectified voltage such that the LED emits light. The rectified voltage indicates a voltage obtained by full-wave rectifying an AC voltage. Since the AC direct-type lighting apparatus uses the rectified voltage without using an inductor and capacitor, the AC direct-type lighting apparatus has a satisfactory power factor.
The AC direct-type lighting apparatus using an LED includes a driver configured to perform current regulation to provide a current path in response to light emission following a change of the rectified voltage.
The driver of the AC direct-type lighting apparatus may be configured to non-linearly control the current in response to the change of the rectified voltage through the current regulation for providing the current path corresponding to the light emission.
The AC direct-type lighting apparatus has high THD due to the non-linear control for the current. Therefore, the lighting apparatus is required to improve power efficiency by reducing THD.